Abstract: A method is described for determining recirculation of blood in a vascular access (11) of a patient undergoing dialysis treatment by means of a dialysis machine (10) comprising an arterial line (24) for withdrawing blood from the patient's body, a dialysis filter (16), and a venous line (26) for returning the blood to the patient's body. The present method consists in inducing, in the blood flowing in the venous line (26), a disturbance of a magnitude such as to bring the system into a transient state and determining blood recirculation in the vascular access (11) during the transient state as a function of the magnitude of the disturbance induced in the arterial line (24). In particular, the aforesaid disturbance consists of the variation of the haemoglobin concentration in the blood flowing in the venous line (26) and the variation is caused by controlling a change in the ultrafiltration flow in dialysis filter (16).

Abstract: A method for continuously determining a parameter (D, Cbin, K, Kt/V) indicative of an extracorporeal blood treatment includes flowing patient's blood and a treatment liquid flow on opposite sides of a semipermeable membrane. The treatment liquid has a characteristic (Cd) associated with the effectiveness of the treatment flow through the exchanger. A succession of variations are caused in the characteristic (Cd) upstream of the exchanger, and a plurality of values (Cdin1 . . . Cdinj . . . Cdinp) of the characteristic (Cd) upstream of the exchanger are continuously stored in memory. Similarly, plurality of values (Cdout1 . . . Cdoutj . . . Cdoutp) adopted by the characteristic (Cd) downstream of the exchanger are continuously stored in memory. From the stored values, the effectiveness of the treatment is calculated using a mathematical model.

Abstract: A method for measuring the hemoglobin concentration (HGB) in the blood in a circuit (2) of a dialysis machine (1), the method comprising the measurement of the values of absorption (A) of electromagnetic waves by the blood conveyed along a specified section (5a) of the said circuit (2), the measurement of the values of a physical quantity iron the group comprising the blood pressure (1)), the blood temperature (T) and the rate of flow (Qb) of the blood along the aforesaid section (5a), and the calculation of the hemoglobin concentration (HGB) as a function of the values of absorption (A) and of the aforesaid physical quantity

Abstract: A method for continuously determining a parameter (D, Cbin, K, Kt/V) indicative of an extracorporeal blood treatment includes flowing patient's blood and a treatment liquid flow on opposite sides of a semipermeable membrane. The treatment liquid has a characteristic (Cd) associated with the effectiveness of the treatment flow through the exchanger. A succession of variations are caused in the characteristic (Cd) upstream of the exchanger, and a plurality of values (Cdin1 . . . Cdinj . . . Cdinp) of the characteristic (Cd) upstream of the exchanger are continuously stored in memory. Similarly, plurality of values (Cdout1 . . . Cdoutj . . . Cdoutp) adopted by the characteristic (Cd) downstream of the exchanger are continuously stored in memory. From the stored values, the effectiveness of the treatment is calculated using a mathematical model.

Abstract: A method for automatic dialysis using a dialysis unit which, in service, is connected to a patient undergoing a dialysis treatment, including the phases of acquiring allowed values of input parameters and desired values of patient parameters, acquiring actual values of the patient parameters, the patient parameters including the relative variation in blood volume (BV) and the weight loss (WL), acquiring actual values of machine parameters including the weight loss rate (WLR) and the conductivity of the (CD) dialysis fluid, and controlling the operation of the dialysis unit using controlled values of the machine parameters to make the patient parameters take on the desired values.

Abstract: A liquid flowed detection system is disclosed for monitoring continuous and discontinuous liquid flow in a fluid circuit. The system includes a holding device for maintaining a drip chamber so that its elongated axis generally lies in a vertical plane. A light emitter is oriented to transmit light along an optical path through the drip chamber and intersecting its elongated axis. A light detector located in the optical path opposite the light emitter, generates a signal representative of light received from the light emitter. A processor receives information from the detector and generates a control signal representative of a variability over time of the light detector signal. When the control signal drops below a predetermined level, a flow absence signal is generated which is then correlated to the system's pump velocity corresponding to a time interval (T). If the flow absence signal occurs continuously in a comparison time interval (T), a warning signal is generated.